So on Fedora 25 with an AMD-8323 (8 core, no hyperthreading) and 24GB of RAM with this hard drive and its 3TB brother in RAID1 , it takes about an hour per Terabyte to do a scrub. (Which seems about equal to what a coworker told me his system takes to do a zfs scrub – 40ish hours for about 40ish TB)